Filtering Needle Cap

ABSTRACT

A filtered needle for use in administering a liquid payload, including a needle and connector portion and a filtering needle cap. The filtering needle cap including a distal open end in fluid communication via an internal channel with a proximal open end of the filtering needle cap. The filtering needle cap proximal end sized to receive the distal end of the hub within the proximal end of the filtering needle cap to reversibly engage the hub when needle distal end is inserted into the internal channel. The filtering needle cap including a filter element and a seal to seal around an outside diameter of the hollow needle so that liquid payload is drawn into the lumen in the hollow needle as liquid payload is filtered and drawn into the fluid fitting. The filtering needle cap is designed to limit a dead volume of liquid payload drawn into the filtering needle cap but not entering into the distal end of the hollow needle.

This application incorporates by reference and claims priority toco-pending Patent Cooperation Treaty Application No. PCT/US2014/038625filed May 19, 2014 for Filtering Needle Cap. The current applicationclaims through the '625 application the benefit of a pair of provisionalapplications: U.S. Provisional Patent Application No. 61/824,486 filedMay 17, 2013 for Filter Needle Cap; and U.S. Provisional PatentApplication No. 61/910,149 filed Nov. 29, 2013 for Filtered Needle, bothof which are incorporated by reference. Likewise, U.S. Pat. No.8,002,751 issued Aug. 23, 2011 for Filter Needle is incorporated byreference. While these applications have been incorporated by referenceto provide additional detail it should be noted that these otherapplications were written at an earlier time and had a different focusfrom the present application. Thus, to the extent that the teachings oruse of terminology differ in any of these incorporated applications fromthe present application, the present application controls.

BACKGROUND Field of the Disclosure

This disclosure relates generally to a filtered needle for safelyadministering pharmaceuticals or other liquid payloads needingfiltration before administration to a patient. The filtered needle maybe used with human patients, veterinary uses for animals, and other usesthat benefit from the filtering of a liquid payload before delivery. Inthis disclosure and the claims that follow, the term needle should beunderstood as a hypodermic needle or analogous needle with an opendistal end and an interior lumen to allow for movement of a liquid.

Liquid pharmaceuticals are typically stored in sealed glass ampoules(often spelled ampule) or other known storage devices. In the case ofglass ampoules, order to gain access to the pharmaceuticals, the ampouleis opened by snapping the glass neck. In so doing, debris in the form ofglass shards may be produced. The shards must be removed from thepharmaceuticals prior to administration. The debris is typically removedby drawing up the pharmaceutical through a filtered cannula or strawsecured to the end of the syringe.

While the most common use of a syringe to deliver liquids is to delivera liquid pharmaceutical, other liquid payloads can be drawn in from areservoir through a filter to remove debris before delivering thefiltered liquid payload through a needle connected to the syringe.

Examples of uses beyond pharmaceuticals include the injection of somenutraceuticals into a patient. Some public health organizations provideneedle exchanges to people addicted to illegal drugs as a way to limitspread of disease and a filtered needle may be of benefit in thisapplication. Some blood products such as PCC (Prothrombin Complex C) usea filtered needle. The list of uses should not be deemed a limitation tothe scope of the claims as those of skill in the art will be able toadapt the teachings of the present disclosure for use with a particularliquid payload and need for filtration.

Methods for removing debris include a two stage process and a one stageprocess. In the two stage process, a needle or straw has a filterelement secured in the needle and connector portion. As the liquidpayload is drawn up into the syringe, the filter traps the debrisremoving it from the liquid payload to be administered. The filteredstraw or needle is then removed from the syringe and discarded. In orderto avoid inadvertent administration of contaminated liquid payload tothe patient care must be taken to remove and discard the filteredneedle. In addition to the danger of mistakenly administering acontaminated liquid payload to a patient, the two stage process mayinvolve the use of specially adapted and costly disposable devices.

U.S. Pat. No. 8,002,751 for Filter Needle discloses a one-step process.This one step process employs a specially fabricated frangible needle orstraw which has a filter secured near the inlet. The needle or straw hasa score line between the filter and the syringe connection. Thepharmaceutical is first drawn up from the ampoule through the filtertrapping the debris. The tip of the needle or straw is then snapped offalong the score line and discarded, taking with it the filter andtrapped debris. The one stage process requires a specially fabricatedneedle or straw which may be snapped off leaving a sharp end foradministering the pharmaceuticals. It is difficult to manufacture aneedle having the required properties. In addition, questions have beenraised as to whether a frangible needle or straw may be produced whichdoes not itself produce debris, such as metal or plastic shards.

Accordingly, an inexpensive and reliable system for filtering liquidpayloads before delivery is desired.

VOCABULARY

Proximal & Distal.

The terms proximal and distal are commonly used when discussing medicaldevices. For the purposes of this application and the claims thatfollow, proximal means the end that is normally held by the user anddistal is the opposite end. This in the case of a hypodermic needle, theend of the needle injected into the patient would be the distal end andthe end manipulated by the user would be the proximal end.

Chamber.

The term chamber is used below in order to describe portions of aninterior pathway through which the liquid payload travels. While in someuses of the word chamber, the chamber may be sealed by closing doors(such as a bed chamber or the judge's chamber), in this context, achamber is a partially enclosed space having an ingress and egress.

Seal.

In the present disclosure and the claims that follow, the term seal isused as the teachings of the present disclosure call for creating a sealbetween the outer perimeter of the needle and the inner perimeter of acannula within the filtering needle cap so that the syringe mayeffectively draw the liquid payload through the interior of the needlewithout pulling air past the seal and into the open distal end of theneedle. A seal adequate for this purpose may not be a sufficient seal tomaintain a more dramatic pressure differential across the seal ormaintain a seal against a more moderate pressure gradient for asubstantial period of time. Thus, in this context, the noun and verbseal indicates a seal sufficient to allow the filtering needle cap toseal around the outer diameter of the needle to allow the syringe todraw in liquid payload.

SUMMARY OF THE DISCLOSURE

Aspects of the teachings contained within this disclosure are addressedin the claims submitted with this application upon filing. Rather thanadding redundant restatements of the contents of the claims, theseclaims should be considered incorporated by reference into this summary.

Some aspects of the present disclosure may be expressed as a filteredneedle for use in administering a liquid payload, the filtered needleincluding a needle and connector portion and a filtering needle cap. Theneedle and connector portion including: a hollow needle with a needledistal end having an opening to a lumen running through the hollowneedle; and a hub. The hub including an open proximal end adapted toreversibly engage a fluid fitting and; a distal end of the hub engagedwith a proximal end of the hollow needle. The filtering needle capincluding a distal open end in fluid communication via an internalchannel with a proximal open end of the filtering needle cap. Thefiltering needle cap proximal end sized to receive the distal end of thehub within the proximal end of the filtering needle cap to reversiblyengage the hub when needle distal end is inserted into the internalchannel. The filtering needle cap including a filter element adapted forremoving debris from the liquid payload as the liquid payload is drawnthrough the filtering needle cap into the lumen within the hollow needleas liquid payload is drawn into the fluid fitting. The filtering needlecap including a seal to seal around an outside diameter of the hollowneedle so that liquid payload is drawn into the lumen in the hollowneedle as liquid payload is drawn into the fluid fitting.

The seal may be placed towards the distal end of the hollow needle sothat the distal end of the seal is closer to the distal end of thehollow needle than to the proximal end of the hollow needle. The distalend of the seal may be distal to a proximal end of the opening to thelumen running through the hollow needle.

Other aspects of the present disclosure may be expressed as a method forloading a quantity of filtered liquid payload into a syringe andconnected hollow needle. The method including the steps of using asyringe to draw in liquid payload from a reservoir of liquid payload,the liquid payload passing through a filter element in a filteringneedle cap before entering an opening in a needle distal end beforeremoving the filtering needle cap from the filtered needle to expose theneedle distal end.

The filtered needle may have a seal. The seal may be placed towards thedistal end of the hollow needle so that the distal end of the seal iscloser to the distal end of the hollow needle than to the proximal endof the hollow needle. The distal end of the seal may be distal to aproximal end of the opening to the lumen running through the hollowneedle.

This summary is meant to provide an introduction to the concepts thatare disclosed within the specification without being an exhaustive listof the many teachings and variations upon those teachings that areprovided in the extended discussion within this disclosure. Thus, thecontents of this summary should not be used to limit the scope of theclaims that follow.

Inventive concepts are illustrated in a series of examples, someexamples showing more than one inventive concept. Individual inventiveconcepts can be implemented without implementing all details provided ina particular example. It is not necessary to provide examples of everypossible combination of the inventive concepts provide below as one ofskill in the art will recognize that inventive concepts illustrated invarious examples can be combined together in order to address a specificapplication.

Other systems, methods, features and advantages of the disclosedteachings will be or will become apparent to one with skill in the artupon examination of the following figures and detailed description. Itis intended that all such additional systems, methods, features andadvantages be included within the scope of and be protected by theaccompanying claims.

BRIEF DESCRIPTION OF THE FIGURES

The disclosure can be better understood with reference to the followingfigures. The components in the figures are not necessarily to scale,emphasis instead being placed upon illustrating the principles of thedisclosure. Moreover, in the figures, like reference numerals designatecorresponding parts throughout the different views.

FIG. 1 is an exploded perspective view of a filtering needle capaccording to a claimed embodiment.

FIG. 2 is an elevation of the arrangement of FIG. 1 in assembled form.

FIG. 3 is a sectional drawing taken along line 3-3 of FIG. 2.

FIG. 4 is a fragmentary enlargement of the filter tip within circulararrow 4 shown in FIG. 3.

FIG. 5 is a fragmentary enlargement of an alternative embodiment of thefilter tip shown in FIG. 4.

FIG. 6 is an exploded perspective view of a filtering needle capaccording to another claimed embodiment.

FIG. 7 is an elevation of the arrangement of FIG. 6 in assembled form.

FIG. 8 is a sectional drawing taken along line 8-8 of FIG. 7.

FIG. 9 is an enlargement of an alternative embodiment of a seal for thefilter tip within circular arrow 9 shown in FIG. 8.

FIG. 10 is a fragmentary enlargement of an alternative embodiment of thefiltering needle cap shown in FIG. 9.

FIG. 11 is an exploded perspective view of a filtering needle capaccording to another claimed embodiment.

FIG. 12 is an elevation of the arrangement of FIG. 11 in assembled form.

FIG. 13 is a sectional illustration of the filtering needle cap takenalong line 13-13 of FIG. 12.

FIG. 14 is a fragmentary enlargement of the filter tip within circulararrow 14 shown in FIG. 13.

FIG. 15 is an exploded perspective view of a filtering needle capaccording to another claimed embodiment.

FIG. 16 is an elevation of the arrangement of FIG. 15 in assembled form.

FIG. 17 is a sectional illustration of the filtering needle cap takenalong line 17-17 of FIG. 16.

FIG. 18 is a fragmentary enlargement of the filter tip within circulararrow 18 shown in FIG. 17.

FIG. 19 is a fragmentary sectional view of a filtering needle capaccording to another embodiment which uses an annular seal.

FIG. 20 shows a portion of a filter tip to highlight the use of atwo-part straw.

FIG. 21 is an exploded perspective view of a filtering needle capaccording to another claimed embodiment.

FIG. 22 is an elevation of the arrangement of FIG. 21 in assembled form.

FIG. 23 is a sectional illustration of the filtering needle cap takenalong line 23-23 of FIG. 22.

FIG. 24 is a fragmentary enlargement of the filter tip within circulararrow 24 shown in FIG. 23.

FIG. 25 illustrates process for use of a filtered needle.

DETAILED DESCRIPTION

The set of figures in FIG. 1 through FIG. 5 illustrate an embodiment ofa filtered needle 10.

FIG. 1 illustrates the filtered needle 10 in exploded perspective form.FIG. 2 is an elevation of the embodiment of FIG. 1 in a fully assembledform, for example, in condition for shipping. FIG. 3 and FIG. 4illustrate sectional and enlarged views of components of the filteredneedle 10. FIG. 5 is an enlargement of an alternative embodiment of thearrangement shown in FIG. 4.

The filtered needle 10 includes an outer cap 12, a filtering needle cap14 coaxially disposed within the outer cap 12 and a needle and connectorportion 16 coaxially disposed within the filtering needle cap 14. Theouter cap 12 has a closed distal end 18, a proximal portion 20 which isopen and an intermediate section 22 having an inner chamber 24 (see FIG.4) for receiving the filtering needle cap 14 therein. FIG. 1 usesbrackets to indicate the scope of the major portions (12, 14, and 16) ofthe filtered needle 10. Subsequent figures use simple lead lines tominimize clutter in the drawings set.

The filtering needle cap 14 has a distal portion 26 which is open; aproximal portion 28 which is also open. The filtering needle cap 14 maybe secured concentrically within the proximal portion 20 of the outercap 12. The filtering needle cap 14 has an intermediate portion 30 whichis hollow and extends into the intermediate section 22 of the outer cap12. A filter element 32 is secured to the distal portion 26 of theintermediate portion 30.

The needle and connector portion 16 has a proximal end 34 which may bein the form of a hub 78 secured within the open proximal portion 28 ofthe filtering needle cap 14. The hub 78 may be adapted to work with aLuer fitting sometimes called a Luer Taper and defined in ISO 594Standards. Luer fittings include those known as Luer-Lock and Luer-Slip(sometimes slip tip). While various Luer fittings are very commonconnection for medical devices, the teachings of the present disclosureare not limited to any specific fitting as other connections could beused.

Frequently, but not always, the connection between the needle and thehub 78 is augmented by an adhesive component. Such an adhesive componentis conventional and not a point of focus for the present disclosure.Thus, details of this adhesive component are not provided. The adhesivecomponent may be considered a part of the hub 78 for the purposes ofthis disclosure and the claims that follow.

A hollow needle 36 is secured to the proximal end 34 of the needle andconnector portion 16 and extends axially within the intermediate portion30 of the filtering needle cap 14 towards the distal portion 26. Theneedle 36 has a distal end 38.

FIG. 4 illustrates a more detailed enlarged view of a distal end of thefiltering needle cap 14. As noted previously, the filter element 32 issecured to the distal portion 26 of the filtering needle cap 14. Thedistal portion 26 has an outer wall 40 with outward projections 48 toretain the filter element 32 by engaging with the inner wall 46 of thefilter element 32. A shoulder 72 separates the filtering needle cap 14distal portion 26 from the filtering needle cap 14 intermediate portion30

Filter element 32 has an inner wall 46 which mates with the outer wall40 with outward projections 48 of the filtering needle cap 14. Theresulting interference fit retains the filter element 32 to the outerwall 40. The filter element 32 has an outer diameter DD corresponding tothat of the intermediate portion 30 as shown. Thus a filtering needlecap 14 with an engaged filter element 32 will have a substantiallysimilar outside diameter DD both proximal and distal of the shoulder 72.

The distal portion 26 of the filtering needle cap 14 may have a smoothcylindrical inner wall 42.

A sealing sleeve 50 is secured within the inner wall 52 of the filteringneedle cap 14 near the distal portion 26 end by suitable barbs ordetents 54. As noted in the alternatives and variation section of thisdisclosure, there are many different ways to connect the variouscomponents and the body of the disclosure will tend to give a singleexample with the knowledge that those of skill in the art can use a widerange of techniques to connect components.

The sealing sleeve 50 has a cylindrical central opening defined by innerwall 58 sized for receiving the needle 36 therein. When the needle 36 ispositioned coaxially within the filtering needle cap 14, as shown inFIG. 2 and FIG. 4, the distal end 38 of the needle 36 engages the innerwall 58 of the sealing sleeve 50 forming a chamber 60 defined by:

-   -   A chamber end 76 of the filter element 32,    -   The inner wall 42 of the distal portion 26 of the filtering        needle cap 14; and    -   A distal end 74 the end of the sealing sleeve 50.

The inner diameter of the inner walls 58 may be less than the outerdiameter of the needle 36 until the needle 36 is inserted through thesealing sleeve 50 to form an interference fit.

The distal end 38 of the needle 36 may be formed with a sharp point asshown in the various drawings of this disclosure. As discussed below,other distal ends including blunt points may be used.

The distal end 38 of the needle extends beyond the sealing sleeve 50into the chamber 60 so that opening 56 may intake liquid payload whenthe syringe is operated. When designing a filtered needle 10, one designcriteria is to minimize the dead volume. Dead volume is the volume ofliquid payload that is drawn in into the filtering needle cap 14 butdoes not enter the opening 56 of the needle 36. The liquid payloadbetween the opening 56 and the distal end of the filtering needle cap 14is discarded when the filtering needle cap 14 is discarded. While someloss of liquid payload is unavoidable as some liquid payload will bewithin the filter element 32, minimizing dead volume remains desirable.Placing the distal end of the sealing sleeve 50 near the opening 56 ofthe needle 36 helps minimize the dead volume. Placing the opening 56 ofthe needle 36 near the proximal end of the filter element 32 helpsminimize the dead volume. Using a reduced bore size on the proximal sideof the filter element 32 helps minimize the dead volume.

Process for Use.

FIG. 25 illustrates process 1000 for loading a filtered needle 10.

Step 1004—Engage Filtered Needle. The filtered needle 10 such as shownin FIG. 2 is secured to the end of a syringe (not shown) or otherfitting by engagement with the hub 78 at the proximal end 34 of theneedle and connector portion 16.

Step 1008—Remove Outer Cap. The outer cap 12 is removed. Note this stepis optional as in some instances the filter needle may be delivered insterile packaging such as a blister pack without an outer cap. In manyinstances the filter needle will be delivered with the needle andconnector portion 16 factory inserted into the filtering needle cap 14and with the outer cap 12 covering a portion of the filtering needle cap14. In order to minimize the chances that the filtering needle cap 14will be separated from the needle and connector portion 16 whenintending to merely remove the outer cap 12, the components may bedesigned so that the force needed to remove the filtering needle cap 14from the needle and connector portion 16 may be significantly more thanthe force needed to remove the outer cap 12 from the filtering needlecap 14. In this context, significantly more would include at leastdouble. The difference in required force may be achieved by havingdifferent degrees of interference fits, or use of different materials orsurface treatments. Other ways of increasing or decreasing the requisiteremoval force will be apparent to those of skill in the art.

Step 1012—Draw Payload into Syringe. The filter element 32 is immersedin an ampoule or suitable receptacle for a liquid payload such as apharmaceutical or other liquid. As the syringe plunger is withdrawn in aknown manner, the liquid payload is drawn up in order to fill thesyringe through a pathway through:

-   -   the filter element 32,    -   the chamber 60; and    -   the interior of the needle 36.

The suction force for drawing up the liquid payload is confined to thepathway by the sealing sleeve 50 which closes the chamber 60. Thesealing sleeve 50 prevents the flow of air in a distal direction fromentering the chamber 60 from the outer perimeter of the needle 36 suchthat the syringe may effectively draw in liquid payload. As the syringeis loaded, any debris in the receptacle of liquid payload drawn up inthe pharmaceutical is trapped in the filter element 32.

Step 1016—Remove Filtering Needle Cap. Once the syringe is loaded, thefiltering needle cap 14 is removed from the needle and connector portion16 by sliding the filtering needle cap 14 off the distal end 38 of theneedle 36. The filtering needle cap 14 may then be discarded along withany debris captured in the filter element 32.

Step 1020—Loaded Syringe is Ready for Use. The syringe is loaded withthe desired amount of liquid payload which has been filtered as theliquid passed through filter element 32. The distal end 38 of the needle36 is exposed and ready for use. Depending on the application, thedistal end 38 of the needle 36 may be inserted as appropriate into apatient's body; to a port with a septum for use with IV therapy, or someother location.

In order to appreciate the benefits of the process for using the variousdisclosed filter needles discussed in this disclosure, it is useful toreview the prior two-step process. In the two stage process, a needle orstraw has a filter element secured in the needle and connector portion.As the liquid payload is drawn up into the syringe, the filter traps thedebris removing it from the liquid payload to be administered. Thefiltered straw or needle is then removed from the syringe and discarded.

Thus, after the liquid payload has been moved into the syringe, thesyringe is disconnected from the filtered straw leaving the distal endof the syringe open and thus providing a path for bacterialcontamination. A needle and connector portion is then connected to thedistal end of the syringe and the liquid payload is now ready fordelivery.

The present process connects the sterile needle and connector portion 16with filtering needle cap 14 and optional outer cap 12 on the distal endof the syringe at the beginning of the process. The distal end of thesyringe is not uncovered until after the delivery of the liquid payloadto patient, IV port, or other desired delivery location. The removal ofthe filtered needle cap 14 unsheathes the distal end 38 of the needle 36without any modification of the pre-existing engagement of the distalend of the syringe and the hub 78. The disclosed process has fewer stepsand less chance for bacterial ingress into the assembly than the priorart two-step process with a filter straw.

FIG. 5 illustrates an alternative arrangement of a filter element 532for filtered needle 510. The filter element 532 has a tail piece 564 onthe proximal end of the filter element 532. The distal end 566 of theintermediate portion 530 of the filtering needle cap 514 is formed witha cylindrical opening 558 sized for closely receiving the tail piece 564of the filter element 532. Inward projections 570 projecting into thecylindrical opening 558 engage the outer wall of the tail piece 564 tosecure the filter element 532 to the filtering needle cap 514 as shown.The filter element 532 has a shoulder 536 to abut the distal end 526 ofthe filtering needle cap 514 so that the diameter of the filter element532 substantially matches the outer diameter of the distal end 526 ofthe filtering needle cap 514. A chamber 560 is formed proximal relativeto the tail piece 564 of the filter element 532 so that the only liquidthat reaches the opening 56 of the needle 36 has been filtered ofdebris.

FIG. 6 through FIG. 9 illustrates another embodiment wherein referencenumbers corresponding to similar features in FIG. 1 through FIG. 5 andare not further described. As shown in FIG. 6, filtered needle 610 hasneedle and connector portion 16, outer cap 12, and filter element 32that may correspond to the items described above. The filtering needlecap 614 differs from the filtering needle cap 14 described above.

FIG. 8 shows the assembled filtered needle 610 with the needle andconnector portion 16 inserted into the filtering needle cap 614 which isinserted into the outer cap 12. FIG. 8 is a cross section of FIG. 7 andshows the portion of FIG. 8 shown in enlarged detail in FIG. 9.

As best seen in FIG. 9, the filter element 32 is retained on the distalportion 26 of the filtering needle cap 614 by outward projections 48.Rather than having a sealing sleeve 50 as discussed above, filteringneedle cap 614 has an interior channel 678 which tapers in a taperingsection 686 from a first section 680 having diameter D to a secondsection 688 with a reduced inner diameter. Inner diameter D is largerthan the outer diameter d of the needle 36. In contrast the diameter ofsecond section 688 receives the distal end 38 of the needle 36 to forman interference fit to substantially seal the interior channel 678. Asthe distal end 38 of the needle 36 is inserted into the filtering needlecap 614, the needle seals the chamber 660 defined by the distal portion26 of the filtering needle cap 614 and the filter element 32. Liquidpayload is filtered while passing through the filter element 32 beforereaching the opening 56 in the distal end 38 of the needle 36.

In the arrangement, the filtering needle cap 614 may be formed of arigid material sized to closely fit or interfere with the outer diameterof the needle 36 so as to form the seal. Alternatively, the filteringneedle cap 614 may be formed of a flexible material and the needle 36may have a diameter which is larger than the inner diameter of thesecond section 688 causing the filtering needle cap 614 to deform as thedistal end 38 of the needle 36 is inserted to form a seal.

FIG. 10 is similar to the arrangement of FIG. 9 except that in thelatter, the filter element 532 with tail piece 564 discussed inconnection with FIG. 5 is used to seal a distal portion 690 of filteringneedle cap 614 which is has the relationship between the distal end 38of the needle 36 with the second section 688 described above. Liquidpayload drawn through the filter element 532 passes through chamber 662into the opening 56 at the distal end 38 of the needle 36.

FIG. 11 through FIG. 14 illustrate an arrangement of an embodiment of afiltered needle 710 with outer cap 712 and needle and connector portion16 having a needle 36 with distal end 38. Filtered needle 710 includesneedle cap 714, filter element 732, and sleeve 708.

FIG. 12 shows an assembled filtered needle 710. FIG. 13 shows a crosssection for FIG. 12 and indicates the region of FIG. 13 shown inenlarged detail in FIG. 14.

Turning now to FIG. 14, when the filtered needle 710 is assembled, theneedle 36 is surrounded by sleeve 708. A filter element 732 ispositioned distal to the sleeve 708 and proximal to a frusta-conicalsegment 720 of the interior bore of the needle cap 714 that transitionsfrom the larger diameter portion 724 of the needle cap 714 to thesmaller diameter portion 728 of the needle cap 714. The filter element732 may be force fit to abut the frusta-conical segment 720 as shown, orthe filter element 732 may be held with detents, not shown, or thefilter element 732 may be held in position by an adhesive. The sleeve708 may likewise be held in position by adhesives, detents or a forcefit.

The needle 36 is fit into an inner channel 740 within the sleeve 708 toform a seal between the needle 36 and the sleeve 708. When the filteredneedle 710 is assembled, the sharp distal end 38 of the needle 36 ispositioned proximal relative to the filter element 732 separated by asmall chamber 736.

When a connected syringe (not shown) draws a liquid payload through thedistal tip of the filtered needle 710, the liquid payload passes throughthe smaller diameter portion 728, the frusta-conical segment 720, thefilter element 732, the small chamber 736, and into an opening 56 in thedistal end 38 of the needle 36.

In the arrangement illustrated the needle cap 714 may be formed of aflexible material which is sized so that the distal end 744 (FIG. 11)thereof may be immersed in an open ampoule for drawing up fluids throughthe filter element 732, thus trapping debris. When the liquid is drawnup, the needle cap 714 may be separated from the needle and connectorportion 16 and discarded. The needle and connector portion 16 with theneedle 36 may thereafter by employed to administer the filtered liquidto the patient either directly or indirectly through an IV.

The seal formed between the needle 36 and the sleeve 708 advantageouslyshields the outer surface of the needle 36 from exposure to liquids. Thesmall chamber 736 desirably limits the volume of liquid which may bewasted when it is drawn up by the syringe as the contents of the smallchamber 736 are discarded with the needle cap 714.

FIG. 15 through FIG. 18 illustrate an embodiment of a filtered needle810. FIG. 15 is an exploded diagram with outer cap 812, filtering needlecap 814, filter element 832, sleeve 808, and needle and connectorportion 16 with needle 36 and distal end 38. FIG. 16 is a view of anassembled filtered needle 810. FIG. 17 is a cross section of FIG. 16 andidentifies the region of FIG. 16 that is shown in enlarged detail inFIG. 18.

Turning now to FIG. 18, the filtering needle cap 814 is formed with anelongated straw portion 848 having uniform outer diameter and aninterior passageway 826, likewise has a uniform diameter. A filterelement 832 is located in the interior passageway 826 distal to thedistal end 38 of the needle 36. The sleeve 808 fills the gap between theouter diameter of the needle 36 and the inner diameter of the interiorpassageway 826 to form a seal. The sleeve 808 may be held in position byinward protrusions 838, adhesives, or an interference fit. A smallchamber 860 exists between the proximal end of the filter element 832and the distal end 38 of the needle 36.

The sleeve 808 may be rigid and rely on close tolerances for aninterference fit with the needle 36 or the sleeve 808 may be elasticallydeformable. After removing the outer cap 812, a syringe may draw liquidpayload through the distal end 844 of the filtering needle cap 814,through the filter element 832, the small chamber 860, and into theopening 56 in the distal end 38 of the needle 36.

FIG. 19 shows a fragmentary detail of a filtered needle 310 withfiltering needle cap 314. Visible in FIG. 19 is the distal end 38 ofneedle 36 extending through sealing annulus 320. The sealing annulus 320is sized to have an open bore with a diameter smaller than the outerdiameter of the needle 36. The sealing annulus 320 may have a taper onthe inner bore to facilitate lead in as the needle 36 is moved distally.As the distal end 38 of the needle 36 is inserted through the sealingannulus 320, a seal is formed and the inner diameter of the sealingannulus 320 will tend to move distally during the deformation of thesealing annulus 320. The sealing annulus 320 may be formed initiallywith the inner diameter of the sealing annulus 320 distal relative tothe connection of the outer diameter of the sealing annulus 320 and theinner wall of the filtering needle cap 314. The seal formed by theinsertion of the needle 36 does not need to be perfect, just sufficientto allow a syringe to draw liquid payload through the opening 56 in thedistal end 38 of the needle 36 after the liquid payload has passedthrough the filter element (not shown here).

FIG. 20 depicts a filtered needle 410 similar to the arrangement shownin FIG. 18, except that the straw portion 848 from FIG. 18 is replacedwith a two-part straw 404 having an interior channel 422. The two-partstraw 404 has a proximal portion 418 and a mating distal portion 414having an overlapping region 450. A sleeve 452 having a cylindricalthrough opening is disposed within the interior channel 422 bridging theoverlapping region 450 securing the proximal portion 418 and the distalportion 414 together. A filter element 432 is located in the interiorchannel 422 above the overlapping region 450 as shown. The needle 36extends through the distal end of the sleeve 452 into a small chamber456 formed between the filter element 432, the distal end of the sleeve452 and the space between the outside diameter of the needle 36 and theinside diameter of the distal portion 414 of the two-part straw 404. Theproximal portion 418 of the two-part straw 404 may be formed of a rigidmaterial; and the distal portion 414 of the two-part straw 404 may beformed of a flexible material to facilitate the drawing up of liquidfrom an ampoule or other liquid reservoir. Thus, the distal portion 414may include a highly flexible portion such as tubing to facilitate theinsertion into a reservoir to draw in liquid payload including liquidpayload in a portion of the liquid reservoir not directly aligned withan opening to the liquid reservoir. Thus, the liquid payload may travelthrough a non-linear path through tubing bent to access the liquidpayload in the liquid reservoir.

FIG. 21 through FIG. 24 illustrates a filtered needle 910. FIG. 21 is anexploded diagram showing an outer cap 912, a filtering needle cap 914and a needle and connector portion 16. Visible within FIG. 21 within thefiltering needle cap 914 are filter element 932, which fits into filterchamber 936 that is formed by open areas within proximal flange 974 anddistal flange 976, and a straw 968.

FIG. 22 shows an assembled filtered needle 910 with outer cap 912,filtering needle cap 914, and needle and connector portion 16. FIG. 23shows a cross section of FIG. 22. FIG. 23 shows the circled area that isenlarged in FIG. 24.

In FIG. 24 the filter element 932 is located in the filter chamber 936that is located between a flanged face of the distal flange 976 andflanged face of the proximal flange 974. One of ordinary skill in theart will recognize that the proximal flange 974 or the distal flange 976could be made deeper and the filter chamber 936 could be placed entirelyin one flange rather than split between the proximal flange 974 and thedistal flange 976. Distal expansion area 996 and proximal expansion area998 increase the wetting area of the filter element 932 to increase theamount of debris that may be removed without materially affecting theability to intake liquid payload across the filter. The increasedwetting area also decreases the pressure drop across the filter element932.

The straw 968 may be inserted into a distal bore 980 in a cylindricalportion 970 connected to the distal flange 976. A shoulder 990 may beused to limit the insertion depth of the straw 968. The cylindricalportion 970 may have a leading taper 994 to assist in placement of theouter cap 912.

As discussed above, the distal end 38 of the needle 36 and proximal bore984 may be sized so that the needle 36 substantially seals the perimeterof the proximal bore 984. Liquid payloads may be drawn by a syringethrough the straw 968, through the filter element 932 in the filterchamber 936 and into a proximal chamber 960 before entering opening 56in the distal end 38 of the needle 36.

One of skill in the art will appreciate that the seal formed between theouter perimeter of the needle 36 and the proximal bore 984 does not needto be perfect as the opening 56 into the needle 36 provides a path ofrelatively low resistance for fluid flow.

Details

Choice of Filter Element.

One design criteria for choice of a filter element on the distal end ofthe filtering needle cap versus a filter element contained internal inthe filtering needle cap is whether collection of abnormal componentswithin the liquid payload is relevant to the application. While allfilter elements may be used to remove shards of glass, in some instancesit may be useful to use a filter element on the distal end of thefiltering needle cap as this distal surface will concentrate certaintypes of abnormal components. For example, some pharmaceuticals maypartially crystalize from age or handling. While a small amount ofcrystallization may be tolerated, an unusual amount of crystallizationmay indicate that the pharmaceutical should be discarded rather thanused. Likewise, some pharmaceuticals may have a small amount of sedimentin the reservoir of the pharmaceutical such as an ampoule, but if alarge amount of sediment appears on the outer surface of the filterelement, the excessive sediment may indicate that the pharmaceutical istoo old or has been compromised by handling.

The filter elements may be sintered filters which have a number oftortuous internal channels for liquid payload to traverse whilecapturing debris. Extending the thickness of the filter increases thedistance that the liquid payload must travel but it also increases thenumber of possible paths for the liquid payload to travel. Thus, forsome range of thicknesses, increasing the thickness decreases theoverall resistance to flow.

One well-known vendor in the field of sintered filter material is thePorex Corporation located in Fairburn Ga. and at www.porex.com.

Alternatives and Variations.

Retention of the Filter Element.

In some of the examples set forth above, the filter element was retainedby protrusions or detents that extended into the filter element tosecure the filter element. Adhesives may be used to secure the filterelement. Many designers may prefer a protrusion or other form ofinterference fit as the use of adhesives might cause adhesives to enterpossible flow paths for liquid payload and thus partially impair thefilter element. Those of skill in the art will recognize that otherattachment methods may be used such at an ultrasonic bond, spin welding,heat welding, and press fit. Likewise, other suggested connectionsbetween components have been provided to provide a suitable example andthose of skill in the art will recognize the many options for connectingtwo components together. The teachings of this present disclosure arenot limited to any particular connection method for joining componentsunless specifically recited in the claims that follow.

Needle Types.

The various figures discussed in connection with this disclosure haveuniformly shown sharp distal ends for the needles. Sharp endedhypodermic needles are particularly adapted for injecting fluidsdirectly into the body of the patient.

In many instances, the liquid payload is not delivered directly into thepatient but is instead delivered to a bag of fluids used in intravenoustherapy (IV therapy). A drip of liquid is provided into a vein of thepatient to slowly provide a desired treatment. The IV fluids aretypically in a bag. Ports with a self-sealing septum may be used to addpharmaceuticals to the liquid being provided in IV therapy. While asharp tipped needle may be used to deliver a liquid payload through aseptum, some prefer using a blunt tip needle. A blunt tip needle reducesthe risk of a needle stick to the medical personnel and may be lessdamaging to the septum. While the variation of needle tips and the bestuses for each type of needle tip is beyond the scope of the presentdisclosure, nothing in this present disclosure limits the teachings toapplications with sharp point needles. Blunt tip needles will haveopenings on their distal portions and one of skill in the art can adaptthe geometries of the filtering needle cap if needed to accommodate thegeometry of various types of blunt tip needles.

Connection to the Hub.

The examples in this disclosure referenced a distal end of a syringeengaging with the hub 78. This may be the most common interaction withthe filter needle, but the teachings of this disclosure could beemployed where there is a combination of components rather than asyringe. For some specific reasons, there may be a series of componentsincluding check-valves, tubing, a syringe, or even a replacement for asyringe that may controllably intake and discharge liquid payloadthrough the needle. The present disclosure may be used as long as thereis an appropriate connection between the filtered needle and theremaining components via the distal fluid fitting of the remainingcomponents.

Sterilization Choices.

Those of skill in the art will recognize that the filtering needle capwith our without an outer cap may be sterilized prior to provision tothe medical facility. Those of skill in the art will recognize thatthere are many different processes such as electron beam processing,gamma ray sterilization, or ethylene oxide gas. Those of skill in theart will recognize that medical devices may be adapted for use with aparticular sterilization process to maximize effectiveness andthroughput. The teachings of the present disclosure may be adapted foruse with a variety of sterilization techniques and thus this aspect ofthe examples was not highlighted or discussed.

Optional Use of Outer Cap.

As noted above, some applications may not use the outer cap but packagethe needle and connector portion along with the filtering needle cap inpackaging such as a blister pack. The packaging would maintain thesterility of the items and would preclude even sterilized debris frombecoming entrained in the filtering needle cap.

One of skill in the art will recognize that some of the alternativeimplementations set forth above are not universally mutually exclusiveand that in some cases additional implementations can be created thatemploy aspects of two or more of the variations described above.Likewise, the present disclosure is not limited to the specific examplesor particular embodiments provided to promote understanding of thevarious teachings of the present disclosure. Moreover, the scope of theclaims which follow covers the range of variations, modifications, andsubstitutes for the components described herein as would be known tothose of skill in the art.

The legal limitations of the scope of the claimed invention are setforth in the claims that follow and extend to cover their legalequivalents. Those unfamiliar with the legal tests for equivalencyshould consult a person registered to practice before the patentauthority which granted this patent such as the United States Patent andTrademark Office or its counterpart.

What is claimed is:
 1. A filtered needle for use in administering aliquid payload, the filtered needle comprising: a needle and connectorportion comprising: a hollow needle with a distal end of the hollowneedle of the hollow needle having an opening to a lumen running throughthe hollow needle; and a hub comprising: an open proximal end adapted toreversibly engage a fluid fitting and; a distal end of the hub engagedwith a proximal end of the hollow needle; and a filtering needle capcomprising: a distal open end in fluid communication via an internalchannel with a proximal open end of the filtering needle cap; theproximal end sized to receive the distal end of the hub within theproximal end of the filtering needle cap to reversibly engage the hubwhen distal end of the hollow needle of the hollow needle is insertedinto the internal channel, a filter element adapted for removing debrisfrom the liquid payload as the liquid payload is drawn through thefiltering needle cap into the lumen within the hollow needle as liquidpayload is drawn into the fluid fitting; a proximal end of the filterelement located near the distal end of the hollow needle so as to reducedead volume; and a seal to seal around an outside diameter of the hollowneedle so that liquid payload is drawn into the lumen in the hollowneedle as liquid payload is drawn into the fluid fitting.
 2. Thefiltered needle of claim 1 wherein the distal end of the hollow needlehas an outer diameter D and a distance between the proximal end of thefilter element and the distal end of the hollow needle is within anorder of magnitude of D.
 3. The filtered needle of claim 1 furthercomprising an outer cap with a closed distal end which may be placedover at least a portion of the filtering needle cap until the filteredneedle is uncovered for filtering liquid payload as liquid payload isdrawn into the fluid fitting.
 4. The filtered needle of claim 3 whereinthe open proximal end of the hub is adapted to reversibly engage thefluid fitting is engaged with a fluid fitting on a distal end of asyringe such that: operation of the syringe to intake liquid payloadthrough the filtered needle with the outer cap removed allows intake ofthe liquid payload that is filtered by the filter element; andsubsequent removal of the filtering needle cap to expose the distal endof the hollow needle allows administration of a volume of filteredliquid payload through operation of the syringe.
 5. The filtered needleof claim 1 wherein a portion of the filter element is a most distalportion of the filtering needle cap so that at least a portion of thefilter element is inserted into a reservoir of liquid payload to intakeliquid payload.
 6. The filtered needle of claim 5 wherein: the seal toseal around the outside diameter of the hollow needle is a sleevelocated within the filtering needle cap between the proximal end of thefiltering needle cap and the filtering element such that the distal endof the hollow needle may be inserted through the sleeve to form anintake flow path for liquid payload comprising: through the filterelement; through the distal open end of the filtering needle cap;through the opening in the distal end of the hollow needle; and throughthe lumen in the hollow needle to the fluid fitting.
 7. The filteredneedle of claim 5 wherein the seal to seal around the outside diameterof the hollow needle is an interference fit between a portion of thehollow needle and a reduced diameter portion of the filtering needle capbetween the proximal end of the filtering needle cap and the filteringelement such that the distal end of the hollow needle may be insertedthrough the reduced diameter portion to form an intake flow path forliquid payload comprising: through the filter element; through thedistal open end of the filtering needle cap; through the opening in thedistal end of the hollow needle; and through the lumen in the hollowneedle to the fluid fitting.
 8. The filtered needle of claim 1 whereinthe filter element is located between the distal open end and theproximal open end of the filtering needle cap such that unfilteredliquid payload may be drawn into the distal open end before passingthrough the filter element.
 9. The filtered needle of claim 8 wherein:the seal to seal around the outside diameter of the hollow needle is asleeve located within the filtering needle cap between the proximal endof the filtering needle cap and the filtering element such that thedistal end of the hollow needle may be inserted through the sleeve toform an intake flow path for liquid payload comprising: through thedistal open end of the filtering needle cap through the filter element;through the opening in the distal end of the hollow needle; and throughthe lumen in the hollow needle to the fluid fitting.
 10. The filteredneedle of claim 8 wherein the seal to seal around the outside diameterof the hollow needle is an interference fit between a portion of thehollow needle and a reduced diameter portion of the filtering needle capbetween the proximal end of the filtering needle cap and the filteringelement such that the distal end of the hollow needle may be insertedthrough the reduced diameter portion to form an intake flow path forliquid payload comprising: through the distal open end of the filteringneedle cap; through the filter element; through the opening in thedistal end of the hollow needle; and through the lumen in the hollowneedle to the fluid fitting.
 11. The filtered needle of claim 8 where atleast a portion of the filtering needle cap is flexible to allow liquidpayload to travel a non-linear path between the distal open end of thefiltering needle cap and the filter element.
 12. The filtered needle ofclaim 1 wherein the fluid fitting is a type of Luer fitting.
 13. Thefiltered needle of claim 1 wherein the hub is engaged with the proximalend of the hollow needle via an adhesive element.
 14. The filteredneedle of claim 1 provided in a kit with a reservoir of liquid payloadwherein the filtered needle may be used with a syringe to filter theliquid payload while loading the syringe before removing the filteringneedle cap and delivering filtered liquid payload through the opening inthe distal end of the hollow needle.
 15. A filtered needle for use inadministering a liquid payload, the filtered needle comprising: a needleand connector portion comprising: a hollow needle with a distal end ofthe hollow needle having an opening to a lumen running through thehollow needle; and a hub comprising: an open proximal end adapted toreversibly engage a fluid fitting and; a distal end of the hub engagedwith a proximal end of the hollow needle; and a filtering needle capcomprising: a distal open end in fluid communication via an internalchannel with a proximal open end of the filtering needle cap; theproximal end sized to receive the distal end of the hub within theproximal end of the filtering needle cap to reversibly engage the hubwhen distal end of the hollow needle is inserted into the internalchannel, a filter element adapted for removing debris from the liquidpayload as the liquid payload is drawn through the filtering needle capinto the lumen within the hollow needle as liquid payload is drawn intothe fluid fitting; and a seal to seal around an outside diameter of thehollow needle so that liquid payload is drawn into the lumen in thehollow needle as liquid payload is drawn into the fluid fitting whereina distal end of the seal is closer to the distal end of the hollowneedle than to the proximal end of the hollow needle.
 16. The filteredneedle of claim 15 wherein the distal end of the seal is distal to aproximal end of the opening to the lumen running through the hollowneedle.
 17. The filtered needle of claim 15 wherein the distal end ofthe hollow needle has an outer diameter D and a distance between aproximal end of the filter element and the distal end of the hollowneedle is within an order of magnitude of D.
 18. A method for loading aquantity of filtered liquid payload into a syringe and connected hollowneedle, the method comprising: obtaining a reservoir of liquid payload;obtaining a syringe attached to a filtered needle, the filtered needlecomprising: a needle and connector portion comprising: a hollow needlewith a distal end of the hollow needle with an opening to a lumenrunning through the hollow needle; and a hub comprising: an openproximal end adapted to reversibly engage a distal end of the syringeand; a distal end of the hub engaged with a proximal end of the hollowneedle; and a filtering needle cap with an intake path including afilter element to filter out debris which may be in the reservoir ofliquid payload, the filtering needle cap having a seal around at least aportion of an outer surface of the needle; wherein a distal end of theseal is closer to the distal end of the hollow needle than to theproximal end of the hollow needle and the distal end of the hollowneedle is close to a proximal end of the filter element so as to limit adead volume of liquid payload drawn into the filtering needle cap butnot entering into the distal end of the hollow needle; using the syringeto draw in liquid payload from the reservoir of liquid payload, theliquid payload passing through the filter element before entering theopening in the distal end of the hollow needle; and removing thefiltering needle cap from the filtered needle to expose the distal endof the hollow needle.
 19. The method of claim 18 wherein the distal endof the hollow needle has an outer diameter D and a distance between theproximal end of the filter element and the distal end of the hollowneedle is within an order of magnitude of D.
 20. The method of claim 18wherein the syringe draws the liquid payload through the filter elementbefore the liquid payload enters an interior channel within thefiltering needle cap.
 21. The method of claim 18 wherein the syringedraws the liquid payload into a distal open end of the filtering needlecap before passing through the filter element.
 22. The method of claim18 wherein the step of obtaining the syringe attached to the filteredneedle comprises: obtaining the filtered needle; obtaining the syringe;and engaging a distal end of the syringe with a proximal end of thefiltered needle.
 23. The method of claim 18 wherein the syringe remainsconnected to the hub continuously from before the syringe is used todrawn in liquid payload through the filter element until after thesyringe is used to deliver at least a portion of the liquid payload to adestination.
 24. The method of claim 18 wherein the filtered needle isinitially sheathed in an outer cap and a force required to remove theouter cap from the filtering needle cap is less than half of a forceneeded for removing the filtering needle cap from the filtered needle toexpose the distal end of the hollow needle.
 25. The method of claim 18wherein the liquid payload is delivered through a septum for use in IVtherapy.